Greenhouses And The Protected Culture Continuum

Greenhouses And The Protected Culture Continuum

Greenhouses are just one step in the continuum for protected cultivation. They just so happen to be at the top of the heap.

Let’s back up a bit.

Crops have been grown outside for thousands of years (perhaps 10,000 years, beginning in the Fertile Crescent, according to theories). But growing outside includes exposure to whatever perils nature throws at the field — torrential rains, parching droughts, scorching heat, and frigid cold, to name just a few Therefore, the concept of trying to protect the crop from some of the most extreme weather fluctuations was conceived.

Protected agriculture has many applications. However, the primary purpose is economic. If a producer can extend the growing season, even just a little earlier or a little later, the value
of the crop goes up.

The grower with the earliest tomatoes, peppers, lettuce, etc. is the one who rakes in the big bucks in those extra weeks of harvest. Likewise with end of season, and harvesting after the competition’s crops have bitten the frozen dust and turned to mush.

Check Out Your Options

We have a whole continuum of options for protecting our crops. Each allows the grower to shield the crop to some extent from extremes in temperature, light, or water, and perhaps offer some protection from insects, diseases, weeds, and air pollutants, as well.

Note that as we move up the ladder and get better protection, the cost of the materials and/or structure goes up sharply. However, the point of this article is that the returns go up even faster.

At the bottom end, mulching the crop is well-known to help with early season warming of the soil, resulting in faster growth of young transplants in early spring, and an earlier first harvest. The most common implementation is black polyethylene mulch, and we can see miles of these 3- to 5-foot-wide plastic ribbons on fields all over the world. It’s cheap, it works, and it brings in the early harvest premium.

Next, row covers, either supported with hoops or floating over the crop, give one more layer of protection. These can be used with or without mulch underneath, but the combination has been clearly shown to increase the benefits of either system alone. These are used worldwide, just like mulch.

Tall Tunnels

The third step would be high tunnels. These are tall enough to walk inside of, and sure look a lot like greenhouses. But they have no utilities, which means no fans, no heat, and no lights.

Sometimes referred to as the “poor man’s greenhouse,” they have found a growing niche with vegetable growers in the U.S. and many other countries. These inexpensive structures can be used for extra-early or extra-late season vegetable, fruit, or flower production. They give more protection than mulch or row covers, and even longer periods of harvest, with resulting better returns. We are seeing more and more of these around the country.

And of course the fourth and top step of the ladder is the bona fide greenhouse. Complete with a heating system, some type of active or passive ventilation, automated fertigation, and often shade cloth and horizontal air flow fans, they provide the best chance for making the environment optimum for vegetable production.

The season extension capabilities are so good that in many parts of the country they are used year-round. This is the Cadillac of protected culture, costs far more than the other systems, but helps producers grow the highest value crops when they cannot be grown outside in the same area. Locally grown vegetables in the winter — that’s what it’s all about.

Back in the Fertile Crescent days, early forms of wheat, barley, flax, peas, lentils, vetch, and chickpeas were the main crops planted in the field. Although important crops even today, compared to modern day horticultural crops, these are very low value on a per acre basis. They are not suitable for greenhouses, row covers, or even mulch.

As you go up the protected culture ladder, the value of the crops selected should go up as well. Vegetable crops are a perfect choice for every rung — their value can be magnified with each step of the continuum. Which season extender will you use next season?

Leave a Reply

Featured Stories

All Vegetables Stories >All Fruits Stories >All Nuts Stories >All Citrus Stories >

The Latest

Vegetables
VegetablesAnnual Santa Maria Vegetable Meeting
August 20, 2014
University of California Cooperative Extension will host annual vegetable meeting focusing on nutrient management, plant growth, weed management, and more. Read More
Leafy Vegetables
Leafy VegetablesTanimura & Antle Introduces New Lettuce Variety 
August 20, 2014
The California grower now offers George T’s Colossal Romaine Heart, in honor of the company's founder, George Tanimura. Read More
Labor
CitrusBorder Crisis Not Helping Farmers
August 19, 2014
As thousands cross into the U.S. seeking refuge, calls for ag labor reform are lost in the uproar. Read More
Cucurbits
Cucurbits24 Sweet Watermelon Varieties [Slideshow]
August 19, 2014
Browse the slideshow below for information on 24 watermelon varieties from the nation’s leading seed breeders and distributors. Read More
Fruits
FruitsHandheld Produce Quality Meter Debuts At 2014 Internati…
August 19, 2014
Researchers to present data measuring dry matter, color, and sugar content of cherries and other product pre- and postharvest. Read More
Grapes
GrapesNew York State Assists Grape Growers Hit By Harsh Winte…
August 19, 2014
State to open winegrape market to grapes grown outside the state. Read More
Marketing
FruitsEuropean Fruit And Vegetable Growers Hit By Russian Ban…
August 19, 2014
Angry at European Union/United States sanctions over Ukraine, Russia has banned many food imports. Read More
Apple Grower of the Year
Apple Grower of the YearGet The Latest News On The Nation’s Apple Crop
August 19, 2014
American and Western Fruit Grower editors will be tweeting in real time this week from the Apple Crop Outlook & Marketing Conference. Read More
Oranges
OrangesSour Forecast For 2014-2015 Florida Orange Crop
August 18, 2014
Paltry prediction signals lowest output in 50 years. Read More
Crop Protection
Crop ProtectionBioConsortia Inc. Bolsters Executive Team
August 18, 2014
Industry veterans Christina Huben and Dr. Susan Turner bring experience to plant biotechnology firm. Read More
Stone Fruit
Stone Fruit‘Ladderless’ Peach, Nectarine Orchards Explored
August 15, 2014
University of California researchers explore the concept of so-called pedestrian orchards. Read More
Farm Management
CitrusU.S. Sugar Buying South Florida Sugar Cane And Vegetabl…
August 15, 2014
Purported deal worth $100 million to purchase farmland and assets of Knight Management Inc. Read More
Farm Management
CitrusFlorida’s Future Farming Leaders Dig Up Knowledge…
August 15, 2014
Class 3 of FFVA's Emerging Leader Development Program learn a lot from road trip to California's Salinas Valley. Read More
Irrigation
CitrusWater Bond Will Appear On California Ballot
August 14, 2014
Voters will decide if thirsty state will spend $7.5 billion, including $2.7 billion for storage. Read More
Berries
BerriesFamiliar Face Settles In As New Florida Strawberry Asso…
August 14, 2014
Kenneth Parker’s deep roots in the community and knowledge of production challenges make a good combination for executive director role. Read More
Insect & Disease Update
Insect & Disease UpdateIs There Light At The End Of The Tunnel For Florida Cit…
August 14, 2014
Time is of the essence in the race to beat greening. Read More
Insect & Disease Update
Insect & Disease UpdateCoca-Cola Shares Additional $1.5 Million To Fight Citru…
August 14, 2014
Grant to help UF/IFAS researchers work toward a solution for devastating disease. Read More
Farm Management
CitrusU.S. Fall Weather Outlook Foresees Wild Ride
August 14, 2014
From continued drought in the West, to a possible early Polar Vortex visit in the East, forecasters are predicting an active autumn. Read More